Spark-plug.



.J. E. MURRAY.

SPARK PLUG. APPLICATION FILED FEB.23, 1907.

1,033,449 w Patented July 23, 1912.

WITNESSES: INVENTOR' ATTORNEY UNITED STATES PATENT oFFion.

JAMES E. M I IBRAY F BROOKLYN, NEW YORK,-A SLGNOR TO ARTHUR R. MOSLER,OF-

NEW YORK, 1v.

SPABK PL UG'.

the production of a plug which will promote I the more economical,effective and advantageous construction and operation of gas enginesfired by electric sparks from diiferent sources by providing a singleplug combining in itself effective means for sparking from two or moredifferent igniting systems.

The invention is particularly applicable for use in automobiles andanalogous constructions. In recent years it-has become customary in theconstruction of such vehicles to provide for ignition from two separatesources of current, usually a battery and a magneto. To secure the bestresults, it is necessary to have the spark plug adapted to the source ofcurrent, as, for example, the distance between the sparking points andthe size of the conductor must vary according to the source and power ofthe current: it has not, therefore, been practicable satisfactorily touse the same spark plug for both sources of current. This has occasionedthe use of two sets .of spark plugs, one adapted to take the currentfrom the battery and the other to take that from the magneto. The resultof this is disadvantageous construction, particularly because thecooling surface of the water-jacket around the cylinders is curtailed bythe space which must be devoted to plugs entering the cylinders andbecause only one system of plugs can be located at the most advantageousfiring position within the cylinders; it involves, moreover, muchunnecessary expense and trouble for the manufacturer and user; anditprecludes the use ofboth ignition systems in engines constructed for asingle system.

' My invention does away with these disadvantages by providing a singlespark plug combining in itself suitable means for firing from two ormore different ignition systems.\

Specification of Letters Patent.

Patented July 23, 1912.

Application filed February 23, 1907. Serial No. 358,803.

There are many well-known constructions of spark plugs, all of whichconsist essentially of a conductor insulated and separated at itssparking point fromthe point of another conductor. The particular forms,materials and fittings used are not important for present purposes,because my invention relates not to details of form, materials orfittings but to the combination in a single plug of sparking meansadapted to two or more distinct ignition systems. i In the accompanyingdrawing is illustrated a simple embodiment of my .invention, the detailsthere shown being obviously susceptible of modification withoutdepartingfrom its spirit or scope.

In the drawings, Figure ,1 is a sectional View taken at the line 1-1 ofthe end view shown in Fig. 2. Fig. 2 is an end viewof the plug.

2 is insulating material, as, for example, mica. through which extendtwo conductors 3 andA- one of Which is connected with the magneto and ispreferably somewhat larger than the other, which is connected with thebattery. The insulating material. 2, preferably extends beyond thesparking points of the conductors 3 and 4 to avoid the possibility ofthe spark jumping from one to the other. This, however, may b vaccomplished in other ways, as, for example, by making the distancebetween the sparking points of the cionductors 3 and 6 and 4' and 7 lessthan the distance between the reminders? and l.

5 is the usual shell.

6 and 7 are sparking points.

8 is the usual binding nut.

It will be'understood that the conductors and insulators may be of anynsu:1l'.usuitable material and that the form illustrated in the drawingmay be variously modified. as these details form no part of theinvention.

I claim 1. In a spark plug, an insulating member. two or more conductorscarried by said member and tcrn'iinating outside of 'said insulatingmember, a portion of said insulating member extending between the c.\'treinities of the conductors.

sides of said projection on said sparking end 2. In a spark plug, thecombination of a with said projection interposed between thenon-conducting core having a sparking 12nd ends thereof. formed with arejection, and a pair of e ec trical conducto s insulated from eachother 7 p I JAMES MURRAY and passing longitudinally through the core,Witnesses: said conductors terminatingpnn opposite HERMAN GUsToW,

DONALD WARDLAW.

Copies of this patent may be obtained Ior five tents each, by addressingthe Commissioner of Patents,

Washington, D. 0.

